//  Copyright 2022 AntGroup CO., Ltd.
//  Licensed under the Apache License, Version 2.0 (the "License");
//  you may not use this file except in compliance with the License.
//  You may obtain a copy of the License at
//  http://www.apache.org/licenses/LICENSE-2.0
//  Unless required by applicable law or agreed to in writing, software
//  distributed under the License is distributed on an "AS IS" BASIS,
//  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

#pragma once

#include <cstdint>
#include <cstring>
#include <algorithm>
#include <exception>
#include <cstddef>
#include <stdexcept>
#include <vector>

#if !defined(__LITTLE_ENDIAN__) && !defined(__BIG_ENDIAN__)
#define __LITTLE_ENDIAN__
#endif

namespace fma_common {
namespace encrypt {

/**
 * Blowfish implementation extracted from: https://github.com/Lsproger/Information_Security
 * public domain code
 */
union Converter32 {
    uint32_t bit_32;
    struct {
#ifdef __LITTLE_ENDIAN__
        uint8_t byte3;
        uint8_t byte2;
        uint8_t byte1;
        uint8_t byte0;
#else
        uint8_t byte0;
        uint8_t byte1;
        uint8_t byte2;
        uint8_t byte3;
#endif
    } bit_8;
};

const uint32_t initial_pary[18] = {0x243f6a88, 0x85a308d3, 0x13198a2e, 0x03707344, 0xa4093822,
                                   0x299f31d0, 0x082efa98, 0xec4e6c89, 0x452821e6, 0x38d01377,
                                   0xbe5466cf, 0x34e90c6c, 0xc0ac29b7, 0xc97c50dd, 0x3f84d5b5,
                                   0xb5470917, 0x9216d5d9, 0x8979fb1b};

const uint32_t initial_sbox[4][256] = {
    {0xd1310ba6, 0x98dfb5ac, 0x2ffd72db, 0xd01adfb7, 0xb8e1afed, 0x6a267e96, 0xba7c9045,
     0xf12c7f99, 0x24a19947, 0xb3916cf7, 0x0801f2e2, 0x858efc16, 0x636920d8, 0x71574e69,
     0xa458fea3, 0xf4933d7e, 0x0d95748f, 0x728eb658, 0x718bcd58, 0x82154aee, 0x7b54a41d,
     0xc25a59b5, 0x9c30d539, 0x2af26013, 0xc5d1b023, 0x286085f0, 0xca417918, 0xb8db38ef,
     0x8e79dcb0, 0x603a180e, 0x6c9e0e8b, 0xb01e8a3e, 0xd71577c1, 0xbd314b27, 0x78af2fda,
     0x55605c60, 0xe65525f3, 0xaa55ab94, 0x57489862, 0x63e81440, 0x55ca396a, 0x2aab10b6,
     0xb4cc5c34, 0x1141e8ce, 0xa15486af, 0x7c72e993, 0xb3ee1411, 0x636fbc2a, 0x2ba9c55d,
     0x741831f6, 0xce5c3e16, 0x9b87931e, 0xafd6ba33, 0x6c24cf5c, 0x7a325381, 0x28958677,
     0x3b8f4898, 0x6b4bb9af, 0xc4bfe81b, 0x66282193, 0x61d809cc, 0xfb21a991, 0x487cac60,
     0x5dec8032, 0xef845d5d, 0xe98575b1, 0xdc262302, 0xeb651b88, 0x23893e81, 0xd396acc5,
     0x0f6d6ff3, 0x83f44239, 0x2e0b4482, 0xa4842004, 0x69c8f04a, 0x9e1f9b5e, 0x21c66842,
     0xf6e96c9a, 0x670c9c61, 0xabd388f0, 0x6a51a0d2, 0xd8542f68, 0x960fa728, 0xab5133a3,
     0x6eef0b6c, 0x137a3be4, 0xba3bf050, 0x7efb2a98, 0xa1f1651d, 0x39af0176, 0x66ca593e,
     0x82430e88, 0x8cee8619, 0x456f9fb4, 0x7d84a5c3, 0x3b8b5ebe, 0xe06f75d8, 0x85c12073,
     0x401a449f, 0x56c16aa6, 0x4ed3aa62, 0x363f7706, 0x1bfedf72, 0x429b023d, 0x37d0d724,
     0xd00a1248, 0xdb0fead3, 0x49f1c09b, 0x075372c9, 0x80991b7b, 0x25d479d8, 0xf6e8def7,
     0xe3fe501a, 0xb6794c3b, 0x976ce0bd, 0x04c006ba, 0xc1a94fb6, 0x409f60c4, 0x5e5c9ec2,
     0x196a2463, 0x68fb6faf, 0x3e6c53b5, 0x1339b2eb, 0x3b52ec6f, 0x6dfc511f, 0x9b30952c,
     0xcc814544, 0xaf5ebd09, 0xbee3d004, 0xde334afd, 0x660f2807, 0x192e4bb3, 0xc0cba857,
     0x45c8740f, 0xd20b5f39, 0xb9d3fbdb, 0x5579c0bd, 0x1a60320a, 0xd6a100c6, 0x402c7279,
     0x679f25fe, 0xfb1fa3cc, 0x8ea5e9f8, 0xdb3222f8, 0x3c7516df, 0xfd616b15, 0x2f501ec8,
     0xad0552ab, 0x323db5fa, 0xfd238760, 0x53317b48, 0x3e00df82, 0x9e5c57bb, 0xca6f8ca0,
     0x1a87562e, 0xdf1769db, 0xd542a8f6, 0x287effc3, 0xac6732c6, 0x8c4f5573, 0x695b27b0,
     0xbbca58c8, 0xe1ffa35d, 0xb8f011a0, 0x10fa3d98, 0xfd2183b8, 0x4afcb56c, 0x2dd1d35b,
     0x9a53e479, 0xb6f84565, 0xd28e49bc, 0x4bfb9790, 0xe1ddf2da, 0xa4cb7e33, 0x62fb1341,
     0xcee4c6e8, 0xef20cada, 0x36774c01, 0xd07e9efe, 0x2bf11fb4, 0x95dbda4d, 0xae909198,
     0xeaad8e71, 0x6b93d5a0, 0xd08ed1d0, 0xafc725e0, 0x8e3c5b2f, 0x8e7594b7, 0x8ff6e2fb,
     0xf2122b64, 0x8888b812, 0x900df01c, 0x4fad5ea0, 0x688fc31c, 0xd1cff191, 0xb3a8c1ad,
     0x2f2f2218, 0xbe0e1777, 0xea752dfe, 0x8b021fa1, 0xe5a0cc0f, 0xb56f74e8, 0x18acf3d6,
     0xce89e299, 0xb4a84fe0, 0xfd13e0b7, 0x7cc43b81, 0xd2ada8d9, 0x165fa266, 0x80957705,
     0x93cc7314, 0x211a1477, 0xe6ad2065, 0x77b5fa86, 0xc75442f5, 0xfb9d35cf, 0xebcdaf0c,
     0x7b3e89a0, 0xd6411bd3, 0xae1e7e49, 0x00250e2d, 0x2071b35e, 0x226800bb, 0x57b8e0af,
     0x2464369b, 0xf009b91e, 0x5563911d, 0x59dfa6aa, 0x78c14389, 0xd95a537f, 0x207d5ba2,
     0x02e5b9c5, 0x83260376, 0x6295cfa9, 0x11c81968, 0x4e734a41, 0xb3472dca, 0x7b14a94a,
     0x1b510052, 0x9a532915, 0xd60f573f, 0xbc9bc6e4, 0x2b60a476, 0x81e67400, 0x08ba6fb5,
     0x571be91f, 0xf296ec6b, 0x2a0dd915, 0xb6636521, 0xe7b9f9b6, 0xff34052e, 0xc5855664,
     0x53b02d5d, 0xa99f8fa1, 0x08ba4799, 0x6e85076a},
    {0x4b7a70e9, 0xb5b32944, 0xdb75092e, 0xc4192623, 0xad6ea6b0, 0x49a7df7d, 0x9cee60b8,
     0x8fedb266, 0xecaa8c71, 0x699a17ff, 0x5664526c, 0xc2b19ee1, 0x193602a5, 0x75094c29,
     0xa0591340, 0xe4183a3e, 0x3f54989a, 0x5b429d65, 0x6b8fe4d6, 0x99f73fd6, 0xa1d29c07,
     0xefe830f5, 0x4d2d38e6, 0xf0255dc1, 0x4cdd2086, 0x8470eb26, 0x6382e9c6, 0x021ecc5e,
     0x09686b3f, 0x3ebaefc9, 0x3c971814, 0x6b6a70a1, 0x687f3584, 0x52a0e286, 0xb79c5305,
     0xaa500737, 0x3e07841c, 0x7fdeae5c, 0x8e7d44ec, 0x5716f2b8, 0xb03ada37, 0xf0500c0d,
     0xf01c1f04, 0x0200b3ff, 0xae0cf51a, 0x3cb574b2, 0x25837a58, 0xdc0921bd, 0xd19113f9,
     0x7ca92ff6, 0x94324773, 0x22f54701, 0x3ae5e581, 0x37c2dadc, 0xc8b57634, 0x9af3dda7,
     0xa9446146, 0x0fd0030e, 0xecc8c73e, 0xa4751e41, 0xe238cd99, 0x3bea0e2f, 0x3280bba1,
     0x183eb331, 0x4e548b38, 0x4f6db908, 0x6f420d03, 0xf60a04bf, 0x2cb81290, 0x24977c79,
     0x5679b072, 0xbcaf89af, 0xde9a771f, 0xd9930810, 0xb38bae12, 0xdccf3f2e, 0x5512721f,
     0x2e6b7124, 0x501adde6, 0x9f84cd87, 0x7a584718, 0x7408da17, 0xbc9f9abc, 0xe94b7d8c,
     0xec7aec3a, 0xdb851dfa, 0x63094366, 0xc464c3d2, 0xef1c1847, 0x3215d908, 0xdd433b37,
     0x24c2ba16, 0x12a14d43, 0x2a65c451, 0x50940002, 0x133ae4dd, 0x71dff89e, 0x10314e55,
     0x81ac77d6, 0x5f11199b, 0x043556f1, 0xd7a3c76b, 0x3c11183b, 0x5924a509, 0xf28fe6ed,
     0x97f1fbfa, 0x9ebabf2c, 0x1e153c6e, 0x86e34570, 0xeae96fb1, 0x860e5e0a, 0x5a3e2ab3,
     0x771fe71c, 0x4e3d06fa, 0x2965dcb9, 0x99e71d0f, 0x803e89d6, 0x5266c825, 0x2e4cc978,
     0x9c10b36a, 0xc6150eba, 0x94e2ea78, 0xa5fc3c53, 0x1e0a2df4, 0xf2f74ea7, 0x361d2b3d,
     0x1939260f, 0x19c27960, 0x5223a708, 0xf71312b6, 0xebadfe6e, 0xeac31f66, 0xe3bc4595,
     0xa67bc883, 0xb17f37d1, 0x018cff28, 0xc332ddef, 0xbe6c5aa5, 0x65582185, 0x68ab9802,
     0xeecea50f, 0xdb2f953b, 0x2aef7dad, 0x5b6e2f84, 0x1521b628, 0x29076170, 0xecdd4775,
     0x619f1510, 0x13cca830, 0xeb61bd96, 0x0334fe1e, 0xaa0363cf, 0xb5735c90, 0x4c70a239,
     0xd59e9e0b, 0xcbaade14, 0xeecc86bc, 0x60622ca7, 0x9cab5cab, 0xb2f3846e, 0x648b1eaf,
     0x19bdf0ca, 0xa02369b9, 0x655abb50, 0x40685a32, 0x3c2ab4b3, 0x319ee9d5, 0xc021b8f7,
     0x9b540b19, 0x875fa099, 0x95f7997e, 0x623d7da8, 0xf837889a, 0x97e32d77, 0x11ed935f,
     0x16681281, 0x0e358829, 0xc7e61fd6, 0x96dedfa1, 0x7858ba99, 0x57f584a5, 0x1b227263,
     0x9b83c3ff, 0x1ac24696, 0xcdb30aeb, 0x532e3054, 0x8fd948e4, 0x6dbc3128, 0x58ebf2ef,
     0x34c6ffea, 0xfe28ed61, 0xee7c3c73, 0x5d4a14d9, 0xe864b7e3, 0x42105d14, 0x203e13e0,
     0x45eee2b6, 0xa3aaabea, 0xdb6c4f15, 0xfacb4fd0, 0xc742f442, 0xef6abbb5, 0x654f3b1d,
     0x41cd2105, 0xd81e799e, 0x86854dc7, 0xe44b476a, 0x3d816250, 0xcf62a1f2, 0x5b8d2646,
     0xfc8883a0, 0xc1c7b6a3, 0x7f1524c3, 0x69cb7492, 0x47848a0b, 0x5692b285, 0x095bbf00,
     0xad19489d, 0x1462b174, 0x23820e00, 0x58428d2a, 0x0c55f5ea, 0x1dadf43e, 0x233f7061,
     0x3372f092, 0x8d937e41, 0xd65fecf1, 0x6c223bdb, 0x7cde3759, 0xcbee7460, 0x4085f2a7,
     0xce77326e, 0xa6078084, 0x19f8509e, 0xe8efd855, 0x61d99735, 0xa969a7aa, 0xc50c06c2,
     0x5a04abfc, 0x800bcadc, 0x9e447a2e, 0xc3453484, 0xfdd56705, 0x0e1e9ec9, 0xdb73dbd3,
     0x105588cd, 0x675fda79, 0xe3674340, 0xc5c43465, 0x713e38d8, 0x3d28f89e, 0xf16dff20,
     0x153e21e7, 0x8fb03d4a, 0xe6e39f2b, 0xdb83adf7},
    {0xe93d5a68, 0x948140f7, 0xf64c261c, 0x94692934, 0x411520f7, 0x7602d4f7, 0xbcf46b2e, 0xd4a20068,
     0xd4082471, 0x3320f46a, 0x43b7d4b7, 0x500061af, 0x1e39f62e, 0x97244546, 0x14214f74, 0xbf8b8840,
     0x4d95fc1d, 0x96b591af, 0x70f4ddd3, 0x66a02f45, 0xbfbc09ec, 0x03bd9785, 0x7fac6dd0, 0x31cb8504,
     0x96eb27b3, 0x55fd3941, 0xda2547e6, 0xabca0a9a, 0x28507825, 0x530429f4, 0x0a2c86da, 0xe9b66dfb,
     0x68dc1462, 0xd7486900, 0x680ec0a4, 0x27a18dee, 0x4f3ffea2, 0xe887ad8c, 0xb58ce006, 0x7af4d6b6,
     0xaace1e7c, 0xd3375fec, 0xce78a399, 0x406b2a42, 0x20fe9e35, 0xd9f385b9, 0xee39d7ab, 0x3b124e8b,
     0x1dc9faf7, 0x4b6d1856, 0x26a36631, 0xeae397b2, 0x3a6efa74, 0xdd5b4332, 0x6841e7f7, 0xca7820fb,
     0xfb0af54e, 0xd8feb397, 0x454056ac, 0xba489527, 0x55533a3a, 0x20838d87, 0xfe6ba9b7, 0xd096954b,
     0x55a867bc, 0xa1159a58, 0xcca92963, 0x99e1db33, 0xa62a4a56, 0x3f3125f9, 0x5ef47e1c, 0x9029317c,
     0xfdf8e802, 0x04272f70, 0x80bb155c, 0x05282ce3, 0x95c11548, 0xe4c66d22,

     0x48c1133f, 0xc70f86dc, 0x07f9c9ee, 0x41041f0f, 0x404779a4, 0x5d886e17, 0x325f51eb, 0xd59bc0d1,
     0xf2bcc18f, 0x41113564, 0x257b7834, 0x602a9c60, 0xdff8e8a3, 0x1f636c1b, 0x0e12b4c2, 0x02e1329e,
     0xaf664fd1, 0xcad18115, 0x6b2395e0, 0x333e92e1, 0x3b240b62, 0xeebeb922, 0x85b2a20e, 0xe6ba0d99,
     0xde720c8c, 0x2da2f728, 0xd0127845, 0x95b794fd, 0x647d0862, 0xe7ccf5f0, 0x5449a36f, 0x877d48fa,
     0xc39dfd27, 0xf33e8d1e, 0x0a476341, 0x992eff74, 0x3a6f6eab, 0xf4f8fd37, 0xa812dc60, 0xa1ebddf8,
     0x991be14c, 0xdb6e6b0d, 0xc67b5510, 0x6d672c37, 0x2765d43b, 0xdcd0e804, 0xf1290dc7, 0xcc00ffa3,
     0xb5390f92, 0x690fed0b, 0x667b9ffb, 0xcedb7d9c, 0xa091cf0b, 0xd9155ea3, 0xbb132f88, 0x515bad24,
     0x7b9479bf, 0x763bd6eb, 0x37392eb3, 0xcc115979, 0x8026e297, 0xf42e312d, 0x6842ada7, 0xc66a2b3b,
     0x12754ccc, 0x782ef11c, 0x6a124237, 0xb79251e7, 0x06a1bbe6, 0x4bfb6350, 0x1a6b1018, 0x11caedfa,
     0x3d25bdd8, 0xe2e1c3c9, 0x44421659, 0x0a121386, 0xd90cec6e, 0xd5abea2a, 0x64af674e, 0xda86a85f,
     0xbebfe988, 0x64e4c3fe, 0x9dbc8057, 0xf0f7c086, 0x60787bf8, 0x6003604d, 0xd1fd8346, 0xf6381fb0,
     0x7745ae04, 0xd736fccc, 0x83426b33, 0xf01eab71, 0xb0804187, 0x3c005e5f, 0x77a057be, 0xbde8ae24,
     0x55464299, 0xbf582e61, 0x4e58f48f, 0xf2ddfda2, 0xf474ef38, 0x8789bdc2, 0x5366f9c3, 0xc8b38e74,
     0xb475f255, 0x46fcd9b9, 0x7aeb2661, 0x8b1ddf84, 0x846a0e79, 0x915f95e2, 0x466e598e, 0x20b45770,
     0x8cd55591, 0xc902de4c, 0xb90bace1, 0xbb8205d0, 0x11a86248, 0x7574a99e, 0xb77f19b6, 0xe0a9dc09,
     0x662d09a1, 0xc4324633, 0xe85a1f02, 0x09f0be8c, 0x4a99a025, 0x1d6efe10, 0x1ab93d1d, 0x0ba5a4df,
     0xa186f20f, 0x2868f169, 0xdcb7da83, 0x573906fe, 0xa1e2ce9b, 0x4fcd7f52, 0x50115e01, 0xa70683fa,
     0xa002b5c4, 0x0de6d027, 0x9af88c27, 0x773f8641, 0xc3604c06, 0x61a806b5, 0xf0177a28, 0xc0f586e0,
     0x006058aa, 0x30dc7d62, 0x11e69ed7, 0x2338ea63, 0x53c2dd94, 0xc2c21634, 0xbbcbee56, 0x90bcb6de,
     0xebfc7da1, 0xce591d76, 0x6f05e409, 0x4b7c0188, 0x39720a3d, 0x7c927c24, 0x86e3725f, 0x724d9db9,
     0x1ac15bb4, 0xd39eb8fc, 0xed545578, 0x08fca5b5, 0xd83d7cd3, 0x4dad0fc4, 0x1e50ef5e, 0xb161e6f8,
     0xa28514d9, 0x6c51133c, 0x6fd5c7e7, 0x56e14ec4, 0x362abfce, 0xddc6c837, 0xd79a3234, 0x92638212,
     0x670efa8e, 0x406000e0},
    {0x3a39ce37, 0xd3faf5cf, 0xabc27737, 0x5ac52d1b, 0x5cb0679e, 0x4fa33742, 0xd3822740,
     0x99bc9bbe, 0xd5118e9d, 0xbf0f7315, 0xd62d1c7e, 0xc700c47b, 0xb78c1b6b, 0x21a19045,
     0xb26eb1be, 0x6a366eb4, 0x5748ab2f, 0xbc946e79, 0xc6a376d2, 0x6549c2c8, 0x530ff8ee,
     0x468dde7d, 0xd5730a1d, 0x4cd04dc6, 0x2939bbdb, 0xa9ba4650, 0xac9526e8, 0xbe5ee304,
     0xa1fad5f0, 0x6a2d519a, 0x63ef8ce2, 0x9a86ee22, 0xc089c2b8, 0x43242ef6, 0xa51e03aa,
     0x9cf2d0a4, 0x83c061ba, 0x9be96a4d, 0x8fe51550, 0xba645bd6, 0x2826a2f9, 0xa73a3ae1,
     0x4ba99586, 0xef5562e9, 0xc72fefd3, 0xf752f7da, 0x3f046f69, 0x77fa0a59, 0x80e4a915,
     0x87b08601, 0x9b09e6ad, 0x3b3ee593, 0xe990fd5a, 0x9e34d797, 0x2cf0b7d9, 0x022b8b51,
     0x96d5ac3a, 0x017da67d, 0xd1cf3ed6, 0x7c7d2d28, 0x1f9f25cf, 0xadf2b89b, 0x5ad6b472,
     0x5a88f54c, 0xe029ac71, 0xe019a5e6, 0x47b0acfd, 0xed93fa9b, 0xe8d3c48d, 0x283b57cc,
     0xf8d56629, 0x79132e28, 0x785f0191, 0xed756055, 0xf7960e44, 0xe3d35e8c, 0x15056dd4,
     0x88f46dba, 0x03a16125, 0x0564f0bd, 0xc3eb9e15, 0x3c9057a2, 0x97271aec, 0xa93a072a,
     0x1b3f6d9b, 0x1e6321f5, 0xf59c66fb, 0x26dcf319, 0x7533d928, 0xb155fdf5, 0x03563482,
     0x8aba3cbb, 0x28517711, 0xc20ad9f8, 0xabcc5167, 0xccad925f, 0x4de81751, 0x3830dc8e,
     0x379d5862, 0x9320f991, 0xea7a90c2, 0xfb3e7bce, 0x5121ce64, 0x774fbe32, 0xa8b6e37e,
     0xc3293d46, 0x48de5369, 0x6413e680, 0xa2ae0810, 0xdd6db224, 0x69852dfd, 0x09072166,
     0xb39a460a, 0x6445c0dd, 0x586cdecf, 0x1c20c8ae, 0x5bbef7dd, 0x1b588d40, 0xccd2017f,
     0x6bb4e3bb, 0xdda26a7e, 0x3a59ff45, 0x3e350a44, 0xbcb4cdd5, 0x72eacea8, 0xfa6484bb,
     0x8d6612ae, 0xbf3c6f47, 0xd29be463, 0x542f5d9e, 0xaec2771b, 0xf64e6370, 0x740e0d8d,
     0xe75b1357, 0xf8721671, 0xaf537d5d, 0x4040cb08, 0x4eb4e2cc, 0x34d2466a, 0x0115af84,
     0xe1b00428, 0x95983a1d, 0x06b89fb4, 0xce6ea048, 0x6f3f3b82, 0x3520ab82, 0x011a1d4b,
     0x277227f8, 0x611560b1, 0xe7933fdc, 0xbb3a792b, 0x344525bd, 0xa08839e1, 0x51ce794b,
     0x2f32c9b7, 0xa01fbac9, 0xe01cc87e, 0xbcc7d1f6, 0xcf0111c3, 0xa1e8aac7, 0x1a908749,
     0xd44fbd9a, 0xd0dadecb, 0xd50ada38, 0x0339c32a, 0xc6913667, 0x8df9317c, 0xe0b12b4f,
     0xf79e59b7, 0x43f5bb3a, 0xf2d519ff, 0x27d9459c, 0xbf97222c, 0x15e6fc2a, 0x0f91fc71,
     0x9b941525, 0xfae59361, 0xceb69ceb, 0xc2a86459, 0x12baa8d1, 0xb6c1075e, 0xe3056a0c,
     0x10d25065, 0xcb03a442, 0xe0ec6e0e, 0x1698db3b, 0x4c98a0be, 0x3278e964, 0x9f1f9532,
     0xe0d392df, 0xd3a0342b, 0x8971f21e, 0x1b0a7441, 0x4ba3348c, 0xc5be7120, 0xc37632d8,
     0xdf359f8d, 0x9b992f2e, 0xe60b6f47, 0x0fe3f11d, 0xe54cda54, 0x1edad891, 0xce6279cf,
     0xcd3e7e6f, 0x1618b166, 0xfd2c1d05, 0x848fd2c5, 0xf6fb2299, 0xf523f357, 0xa6327623,
     0x93a83531, 0x56cccd02, 0xacf08162, 0x5a75ebb5, 0x6e163697, 0x88d273cc, 0xde966292,
     0x81b949d0, 0x4c50901b, 0x71c65614, 0xe6c6c7bd, 0x327a140a, 0x45e1d006, 0xc3f27b9a,
     0xc9aa53fd, 0x62a80f00, 0xbb25bfe2, 0x35bdd2f6, 0x71126905, 0xb2040222, 0xb6cbcf7c,
     0xcd769c2b, 0x53113ec0, 0x1640e3d3, 0x38abbd60, 0x2547adf0, 0xba38209c, 0xf746ce76,
     0x77afa1c5, 0x20756060, 0x85cbfe4e, 0x8ae88dd8, 0x7aaaf9b0, 0x4cf9aa7e, 0x1948c25c,
     0x02fb8a8c, 0x01c36ae4, 0xd6ebe1f9, 0x90d4f869, 0xa65cdea0, 0x3f09252d, 0xc208e69f,
     0xb74e6132, 0xce77e25b, 0x578fdfe3, 0x3ac372e6}};

inline size_t GCD(size_t larger, size_t smaller) {
    size_t gcd = smaller;
    size_t gcd_prev = larger;
    size_t gcd_next;

    while ((gcd_next = gcd_prev % gcd) != 0) {
        gcd_prev = gcd;
        gcd = gcd_next;
    }

    return gcd;
}

inline size_t PKCS5PaddingLength(const std::string& data) {
    if (data.empty()) return 0;
    char length = data[data.size() - 1];
    if (length > 0 && length <= 8) {
        for (char i = 0; i < length; ++i) {
            if (length != data[data.size() - i - 1]) {
                return 0;
            }
        }
    } else {
        return 0;
    }
    return length;
}

class Blowfish {
 public:
    explicit Blowfish(const std::string& key) { SetKey(key.data(), key.size()); }

    std::string Encrypt(const std::string& src) const {
        std::string dst = src;

        size_t padding_length = dst.size() % sizeof(uint64_t);
        if (padding_length == 0) {
            padding_length = sizeof(uint64_t);
        } else {
            padding_length = sizeof(uint64_t) - padding_length;
        }

        for (size_t i = 0; i < padding_length; ++i) {
            dst.push_back(static_cast<char>(padding_length));
        }

        for (size_t i = 0; i < dst.size() / sizeof(uint64_t); ++i) {
            uint32_t* base = (uint32_t*)dst.data();
            uint32_t* left = &(base)[i * 2];
            uint32_t* right = &(base)[i * 2 + 1];
            EncryptBlock(left, right);
        }

        return dst;
    }

    std::string Decrypt(const std::string& src) const {
        std::string dst = src;

        for (size_t i = 0; i < dst.size() / sizeof(uint64_t); ++i) {
            uint32_t* base = (uint32_t*)dst.data();
            uint32_t* left = &(base)[i * 2];
            uint32_t* right = &(base)[i * 2 + 1];
            DecryptBlock(left, right);
        }

        size_t padding_length = PKCS5PaddingLength(dst);
        dst.resize(dst.size() - padding_length);
        return dst;
    }

 private:
    void SetKey(const char* key, size_t byte_length) {
        std::memcpy(pary_, initial_pary, sizeof(initial_pary));
        std::memcpy(sbox_, initial_sbox, sizeof(initial_sbox));

        static const int pary_length = sizeof(pary_) / sizeof(uint32_t);
        static const int sbox_length = sizeof(sbox_) / sizeof(uint32_t);

        {
            size_t buffer_length = byte_length / GCD(byte_length, sizeof(uint32_t));
            uint32_t* key_buffer = new uint32_t[buffer_length];

            for (size_t i = 0; i < buffer_length; ++i) {
                Converter32 converter;

                converter.bit_8.byte0 = key[(i * 4) % byte_length];
                converter.bit_8.byte1 = key[(i * 4 + 1) % byte_length];
                converter.bit_8.byte2 = key[(i * 4 + 2) % byte_length];
                converter.bit_8.byte3 = key[(i * 4 + 3) % byte_length];

                key_buffer[i] = converter.bit_32;
            }

            for (int i = 0; i < pary_length; ++i) {
                uint32_t key_uint32 = key_buffer[i % buffer_length];
                pary_[i] ^= key_uint32;
            }

            delete[] key_buffer;
        }

        uint32_t left = 0x00000000;
        uint32_t right = 0x00000000;

        for (int i = 0; i < (pary_length / 2); ++i) {
            EncryptBlock(&left, &right);

            pary_[i * 2] = left;
            pary_[i * 2 + 1] = right;
        }

        for (int i = 0; i < (sbox_length / 2); ++i) {
            EncryptBlock(&left, &right);

            reinterpret_cast<uint32_t*>(sbox_)[i * 2] = left;
            reinterpret_cast<uint32_t*>(sbox_)[i * 2 + 1] = right;
        }
    }

    void EncryptBlock(uint32_t* left, uint32_t* right) const {
        for (int i = 0; i < 16; ++i) {
            *left ^= pary_[i];
            *right ^= Feistel(*left);
            std::swap(*left, *right);
        }

        std::swap(*left, *right);

        *right ^= pary_[16];
        *left ^= pary_[17];
    }

    void DecryptBlock(uint32_t* left, uint32_t* right) const {
        for (int i = 0; i < 16; ++i) {
            *left ^= pary_[17 - i];
            *right ^= Feistel(*left);
            std::swap(*left, *right);
        }

        std::swap(*left, *right);

        *right ^= pary_[1];
        *left ^= pary_[0];
    }

    uint32_t Feistel(uint32_t value) const {
        Converter32 converter;
        converter.bit_32 = value;

        uint8_t a = converter.bit_8.byte0;
        uint8_t b = converter.bit_8.byte1;
        uint8_t c = converter.bit_8.byte2;
        uint8_t d = converter.bit_8.byte3;

        return ((sbox_[0][a] + sbox_[1][b]) ^ sbox_[2][c]) + sbox_[3][d];
    }

 private:
    uint32_t pary_[18]{};
    uint32_t sbox_[4][256]{};
};

template <typename ENG>
class Encryptor {
    ENG eng_;
    uint32_t GetMagic() const {
        static uint32_t MAGIC = 0x20020718;
        return MAGIC;
    }

 public:
    explicit Encryptor(const std::string& key) : eng_(key) {}

    std::string Encrypt(const std::string& str) const {
        std::string to_enc;
        uint32_t MAGIC = GetMagic();
        to_enc.append((const char*)&MAGIC, sizeof(MAGIC));
        size_t s = str.size();
        to_enc.append((const char*)&s, sizeof(s));
        to_enc.append(str);
        return eng_.Encrypt(to_enc);
    }

    std::string Decrypt(const std::string& str) const {
        std::string dec = eng_.Decrypt(str);
        uint32_t MAGIC = GetMagic();
        size_t min_size = sizeof(MAGIC) + sizeof(size_t);
        if (dec.size() < min_size) throw std::runtime_error("failed to decipher");
        decltype(MAGIC) magic = *(decltype(MAGIC)*)dec.data();
        if (magic != MAGIC) throw std::runtime_error("failed to decipher");
        size_t s = *(size_t*)(dec.data() + sizeof(MAGIC));
        if (s > dec.size() - min_size) throw std::runtime_error("failed to decipher");
        return dec.substr(min_size, s);
    }
};

class MD5 {
    /*
     * This code implements the MD5 message-digest algorithm.
     * The algorithm is due to Ron Rivest.	This code was
     * written by Colin Plumb in 1993, no copyright is claimed.
     * This code is in the public domain; do with it what you wish.
     *
     * Equivalent code is available from RSA Data Security, Inc.
     * This code has been tested against that, and is equivalent,
     * except that you don't need to include two pages of legalese
     * with every copy.
     *
     * To compute the message digest of a chunk of bytes, declare an
     * MD5Context structure, pass it to MD5Init, call MD5Update as
     * needed on buffers full of bytes, and then call MD5Final, which
     * will fill a supplied 16-byte array with the digest.
     */

    /* Brutally hacked by John Walker back from ANSI C to K&R (no
       prototypes) to maintain the tradition that Netfone will compile
       with Sun's original "cc". */

    struct MD5Context {
        uint32_t buf[4];
        uint32_t bits[2];
        unsigned char in[64];
    };

    MD5Context context_{};

#ifndef FMA_BIG_ENDIAN
#define byteReverse(buf, len) /* Nothing */
#else
    /*
     * Note: this code is harmless on little-endian machines.
     */
    static void byteReverse(buf, longs) unsigned char* buf;
    unsigned longs;
    {
        uint32_t t;
        do {
            t = (uint32)((unsigned)buf[3] << 8 | buf[2]) << 16 | ((unsigned)buf[1] << 8 | buf[0]);
            *(uint32*)buf = t;
            buf += 4;
        } while (--longs);
    }
#endif

    /*
     * Start MD5 accumulation.  Set bit count to 0 and buffer to mysterious
     * initialization constants.
     */
    static void MD5Init(MD5Context* ctx) {
        ctx->buf[0] = 0x67452301;
        ctx->buf[1] = 0xefcdab89;
        ctx->buf[2] = 0x98badcfe;
        ctx->buf[3] = 0x10325476;

        ctx->bits[0] = 0;
        ctx->bits[1] = 0;
    }

    /*
     * Update context to reflect the concatenation of another buffer full
     * of bytes.
     */
    static void MD5Update(MD5Context* ctx, unsigned char* buf, unsigned len) {
        uint32_t t;
        /* Update bitcount */
        t = ctx->bits[0];
        if ((ctx->bits[0] = t + ((uint32_t)len << 3)) < t)
            ctx->bits[1]++; /* Carry from low to high */
        ctx->bits[1] += len >> 29;
        t = (t >> 3) & 0x3f; /* Bytes already in shsInfo->data */
        /* Handle any leading odd-sized chunks */
        if (t) {
            unsigned char* p = (unsigned char*)ctx->in + t;

            t = 64 - t;
            if (len < t) {
                memcpy(p, buf, len);
                return;
            }
            memcpy(p, buf, t);
            byteReverse(ctx->in, 16);
            MD5Transform(ctx->buf, (uint32_t*)ctx->in);
            buf += t;
            len -= t;
        }
        /* Process data in 64-byte chunks */
        while (len >= 64) {
            memcpy(ctx->in, buf, 64);
            byteReverse(ctx->in, 16);
            MD5Transform(ctx->buf, (uint32_t*)ctx->in);
            buf += 64;
            len -= 64;
        }
        /* Handle any remaining bytes of data. */
        memcpy(ctx->in, buf, len);
    }

    /*
     * Final wrapup - pad to 64-byte boundary with the bit pattern
     * 1 0* (64-bit count of bits processed, MSB-first)
     */
    static void MD5Final(unsigned char digest[], MD5Context* ctx) {
        unsigned count;
        unsigned char* p;
        /* Compute number of bytes mod 64 */
        count = (ctx->bits[0] >> 3) & 0x3F;
        /* Set the first char of padding to 0x80.  This is safe since there is
           always at least one byte free */
        p = ctx->in + count;
        *p++ = 0x80;
        /* Bytes of padding needed to make 64 bytes */
        count = 64 - 1 - count;
        /* Pad out to 56 mod 64 */
        if (count < 8) {
            /* Two lots of padding:  Pad the first block to 64 bytes */
            memset(p, 0, count);
            byteReverse(ctx->in, 16);
            MD5Transform(ctx->buf, (uint32_t*)ctx->in);

            /* Now fill the next block with 56 bytes */
            memset(ctx->in, 0, 56);
        } else {
            /* Pad block to 56 bytes */
            memset(p, 0, count - 8);
        }
        byteReverse(ctx->in, 14);
        /* Append length in bits and transform */
        ((uint32_t*)ctx->in)[14] = ctx->bits[0];
        ((uint32_t*)ctx->in)[15] = ctx->bits[1];
        MD5Transform(ctx->buf, (uint32_t*)ctx->in);
        byteReverse((unsigned char*)ctx->buf, 4);
        memcpy(digest, ctx->buf, 16);
        memset(ctx, 0, sizeof(MD5Context)); /* In case it's sensitive */
    }

/* The four core functions - F1 is optimized somewhat */

/* #define F1(x, y, z) (x & y | ~x & z) */
#define _MD5_F1(x, y, z) (z ^ (x & (y ^ z)))
#define _MD5_F2(x, y, z) _MD5_F1(z, x, y)
#define _MD5_F3(x, y, z) (x ^ y ^ z)
#define _MD5_F4(x, y, z) (y ^ (x | ~z))

/* This is the central step in the MD5 algorithm. */
#define MD5STEP(f, w, x, y, z, data, s) (w += f(x, y, z) + data, w = w << s | w >> (32 - s), w += x)

    /*
     * The core of the MD5 algorithm, this alters an existing MD5 hash to
     * reflect the addition of 16 longwords of new data.  MD5Update blocks
     * the data and converts bytes into longwords for this routine.
     */
    static void MD5Transform(uint32_t buf[], uint32_t in[]) {
        uint32_t a, b, c, d;
        a = buf[0];
        b = buf[1];
        c = buf[2];
        d = buf[3];
        MD5STEP(_MD5_F1, a, b, c, d, in[0] + 0xd76aa478, 7);
        MD5STEP(_MD5_F1, d, a, b, c, in[1] + 0xe8c7b756, 12);
        MD5STEP(_MD5_F1, c, d, a, b, in[2] + 0x242070db, 17);
        MD5STEP(_MD5_F1, b, c, d, a, in[3] + 0xc1bdceee, 22);
        MD5STEP(_MD5_F1, a, b, c, d, in[4] + 0xf57c0faf, 7);
        MD5STEP(_MD5_F1, d, a, b, c, in[5] + 0x4787c62a, 12);
        MD5STEP(_MD5_F1, c, d, a, b, in[6] + 0xa8304613, 17);
        MD5STEP(_MD5_F1, b, c, d, a, in[7] + 0xfd469501, 22);
        MD5STEP(_MD5_F1, a, b, c, d, in[8] + 0x698098d8, 7);
        MD5STEP(_MD5_F1, d, a, b, c, in[9] + 0x8b44f7af, 12);
        MD5STEP(_MD5_F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
        MD5STEP(_MD5_F1, b, c, d, a, in[11] + 0x895cd7be, 22);
        MD5STEP(_MD5_F1, a, b, c, d, in[12] + 0x6b901122, 7);
        MD5STEP(_MD5_F1, d, a, b, c, in[13] + 0xfd987193, 12);
        MD5STEP(_MD5_F1, c, d, a, b, in[14] + 0xa679438e, 17);
        MD5STEP(_MD5_F1, b, c, d, a, in[15] + 0x49b40821, 22);

        MD5STEP(_MD5_F2, a, b, c, d, in[1] + 0xf61e2562, 5);
        MD5STEP(_MD5_F2, d, a, b, c, in[6] + 0xc040b340, 9);
        MD5STEP(_MD5_F2, c, d, a, b, in[11] + 0x265e5a51, 14);
        MD5STEP(_MD5_F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);
        MD5STEP(_MD5_F2, a, b, c, d, in[5] + 0xd62f105d, 5);
        MD5STEP(_MD5_F2, d, a, b, c, in[10] + 0x02441453, 9);
        MD5STEP(_MD5_F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
        MD5STEP(_MD5_F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);
        MD5STEP(_MD5_F2, a, b, c, d, in[9] + 0x21e1cde6, 5);
        MD5STEP(_MD5_F2, d, a, b, c, in[14] + 0xc33707d6, 9);
        MD5STEP(_MD5_F2, c, d, a, b, in[3] + 0xf4d50d87, 14);
        MD5STEP(_MD5_F2, b, c, d, a, in[8] + 0x455a14ed, 20);
        MD5STEP(_MD5_F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
        MD5STEP(_MD5_F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);
        MD5STEP(_MD5_F2, c, d, a, b, in[7] + 0x676f02d9, 14);
        MD5STEP(_MD5_F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);

        MD5STEP(_MD5_F3, a, b, c, d, in[5] + 0xfffa3942, 4);
        MD5STEP(_MD5_F3, d, a, b, c, in[8] + 0x8771f681, 11);
        MD5STEP(_MD5_F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
        MD5STEP(_MD5_F3, b, c, d, a, in[14] + 0xfde5380c, 23);
        MD5STEP(_MD5_F3, a, b, c, d, in[1] + 0xa4beea44, 4);
        MD5STEP(_MD5_F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);
        MD5STEP(_MD5_F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);
        MD5STEP(_MD5_F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
        MD5STEP(_MD5_F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
        MD5STEP(_MD5_F3, d, a, b, c, in[0] + 0xeaa127fa, 11);
        MD5STEP(_MD5_F3, c, d, a, b, in[3] + 0xd4ef3085, 16);
        MD5STEP(_MD5_F3, b, c, d, a, in[6] + 0x04881d05, 23);
        MD5STEP(_MD5_F3, a, b, c, d, in[9] + 0xd9d4d039, 4);
        MD5STEP(_MD5_F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
        MD5STEP(_MD5_F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
        MD5STEP(_MD5_F3, b, c, d, a, in[2] + 0xc4ac5665, 23);

        MD5STEP(_MD5_F4, a, b, c, d, in[0] + 0xf4292244, 6);
        MD5STEP(_MD5_F4, d, a, b, c, in[7] + 0x432aff97, 10);
        MD5STEP(_MD5_F4, c, d, a, b, in[14] + 0xab9423a7, 15);
        MD5STEP(_MD5_F4, b, c, d, a, in[5] + 0xfc93a039, 21);
        MD5STEP(_MD5_F4, a, b, c, d, in[12] + 0x655b59c3, 6);
        MD5STEP(_MD5_F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);
        MD5STEP(_MD5_F4, c, d, a, b, in[10] + 0xffeff47d, 15);
        MD5STEP(_MD5_F4, b, c, d, a, in[1] + 0x85845dd1, 21);
        MD5STEP(_MD5_F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);
        MD5STEP(_MD5_F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
        MD5STEP(_MD5_F4, c, d, a, b, in[6] + 0xa3014314, 15);
        MD5STEP(_MD5_F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
        MD5STEP(_MD5_F4, a, b, c, d, in[4] + 0xf7537e82, 6);
        MD5STEP(_MD5_F4, d, a, b, c, in[11] + 0xbd3af235, 10);
        MD5STEP(_MD5_F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);
        MD5STEP(_MD5_F4, b, c, d, a, in[9] + 0xeb86d391, 21);

        buf[0] += a;
        buf[1] += b;
        buf[2] += c;
        buf[3] += d;
    }

 public:
    static inline std::string Encrypt(const std::string& str, const std::string& salt = "") {
        MD5Context context;
        MD5Init(&context);
        MD5Update(&context, (unsigned char*)str.data(), static_cast<unsigned int>(str.size()));
        if (!salt.empty()) {
            MD5Update(&context, (unsigned char*)salt.data(),
                      static_cast<unsigned int>(salt.size()));
        }
        std::string digest(16, 0);
        MD5Final((unsigned char*)digest.data(), &context);
        return digest;
    }

    explicit MD5(const std::string& salt = "") {
        MD5Init(&context_);
        if (!salt.empty())
            MD5Update(&context_, (unsigned char*)salt.data(),
                      static_cast<unsigned int>(salt.size()));
    }

    void Update(const char* buf, size_t s) {
        MD5Update(&context_, (unsigned char*)buf, static_cast<unsigned int>(s));
    }

    std::string GetDigest() {
        std::string digest(16, 0);
        MD5Final((unsigned char*)digest.data(), &context_);
        return digest;
    }
};

class Base64 {
 public:
    inline std::string Encode(const char* p, size_t s) {
        static const char* tbl =
            "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
            "abcdefghijklmnopqrstuvwxyz"
            "0123456789+/";
        size_t ngroup = (s + 2) / 3;
        std::string ret(ngroup * 4, '=');
        for (size_t g = 0; g < s / 3; g++) {
            // handle a full group
            const uint8_t* sp = (const uint8_t*)p + g * 3;
            char* dp = &ret[g * 4];
            dp[0] = tbl[sp[0] >> 2];
            dp[1] = tbl[((sp[0] & 0x3) << 4) + ((sp[1] & 0xF0) >> 4)];
            dp[2] = tbl[((sp[1] & 0x0F) << 2) + (sp[2] >> 6)];
            dp[3] = tbl[sp[2] & 0x3F];
        }
        // handle left-overs
        size_t ns = s % 3;
        if (ns != 0) {
            char* dp = &ret[(ngroup - 1) * 4];
            const uint8_t* sp = (const uint8_t*)p + (s - ns);
            dp[0] = tbl[sp[0] >> 2];
            if (ns == 1) {
                dp[1] = tbl[(sp[0] & 0x3) << 4];
                return ret;
            }
            // ns == 2
            dp[1] = tbl[((sp[0] & 0x3) << 4) + ((sp[1] & 0xF0) >> 4)];
            dp[2] = tbl[(sp[1] & 0x0F) << 2];
        }
        return ret;
    }

    inline std::string Encode(const std::string& str) { return Encode(str.data(), str.size()); }

    inline bool TryDecode(const char* p, size_t s, std::string& ret) {
        static const uint8_t tbl[256] = {
            128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128,
            128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128,
            128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 62,  128, 128, 128, 63,
            52,  53,  54,  55,  56,  57,  58,  59,  60,  61,  128, 128, 128, 0,   128, 128,
            128, 0,   1,   2,   3,   4,   5,   6,   7,   8,   9,   10,  11,  12,  13,  14,
            15,  16,  17,  18,  19,  20,  21,  22,  23,  24,  25,  128, 128, 128, 128, 128,
            128, 26,  27,  28,  29,  30,  31,  32,  33,  34,  35,  36,  37,  38,  39,  40,
            41,  42,  43,  44,  45,  46,  47,  48,  49,  50,  51,  128, 128, 128, 128, 128,
            128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128,
            128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128,
            128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128,
            128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128,
            128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128,
            128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128,
            128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128,
            128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128,
        };

        if (s % 4 != 0) return false;
        ret.resize((s / 4) * 3);
        if (s == 0) return true;
        size_t npad = 0;
        if (p[s - 1] == '=') {
            npad = (p[s - 2] == '=') ? 2 : 1;
        }
        for (size_t g = 0; g < s / 4; g++) {
            const uint8_t* sp = (uint8_t*)p + g * 4;
            uint8_t* dp = (uint8_t*)&ret[0] + g * 3;
            uint8_t s0 = tbl[sp[0]];
            uint8_t s1 = tbl[sp[1]];
            uint8_t s2 = tbl[sp[2]];
            uint8_t s3 = tbl[sp[3]];
            if ((s0 | s1 | s2 | s3) >= 128) {
                return false;  // check that all are valid
            }
            dp[0] = (s0 << 2) + ((s1 & 0x30) >> 4);
            dp[1] = ((s1 & 0x0F) << 4) + ((s2 & 0x3C) >> 2);
            dp[2] = ((s2 & 0x03) << 6) + s3;
        }
        ret.resize(ret.size() - npad);  // remove padding
        return true;
    }

    inline bool TryDecode(const std::string& str, std::string& out) {
        return TryDecode(str.data(), str.size(), out);
    }

    inline std::string Decode(const char* p, size_t s) {
        std::string ret;
        if (!TryDecode(p, s, ret)) throw std::runtime_error("Failed to decode Base64 string.");
        return ret;
    }

    inline std::string Decode(const std::string& str) { return Decode(str.data(), str.size()); }
};

class Base16 {
 public:
    static std::string Encode(const std::string& str) {
        static const char* tbl = "0123456789ABCDEF";
        std::string ret(str.size() * 2, 0);
        for (size_t i = 0; i < str.size(); i++) {
            uint8_t c = (uint8_t)str[i];
            ret[2 * i] = tbl[(c & 0xF0) >> 4];
            ret[2 * i + 1] = tbl[c & 0xF];
        }
        return ret;
    }

    static std::string Decode(const std::string& encrypted) {
        static const uint8_t tbl[256] = {
            255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
            255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
            255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
            0,   1,   2,   3,   4,   5,   6,   7,   8,   9,   255, 255, 255, 255, 255, 255,
            255, 10,  11,  12,  13,  14,  15,  255, 255, 255, 255, 255, 255, 255, 255, 255,
            255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
            255, 10,  11,  12,  13,  14,  15,  255, 255, 255, 255, 255, 255, 255, 255, 255,
            255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
            255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
            255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
            255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
            255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
            255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
            255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
            255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
            255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
        };
        if (encrypted.size() % 2 != 0)
            throw std::runtime_error("Failed to decode hex16 string: odd input size.");
        std::string ret(encrypted.size() / 2, 0);
        for (size_t i = 0; i < encrypted.size(); i += 2) {
            uint8_t upper = tbl[(uint8_t)encrypted[i]];
            uint8_t lower = tbl[(uint8_t)encrypted[i + 1]];
            if (upper == 255 || lower == 255)
                throw std::runtime_error("Failed to decode hex16 string: illegal chars.");
            ret[i / 2] = (char)((upper << 4) + lower);
        }
        return ret;
    }
};
}  // namespace encrypt
}  // namespace fma_common
